Cataract

Introduction

A cataract is an opacity or cloudiness of the eye’s natural lens. Located behind the coloured iris, the lens is responsible for focusing light and producing a clear image on the retina at the back of the eye. When the lens develops opacity, light cannot pass to the retina and the resulting image appears blurred or ‘cloudy’. Compare a clear glass window to a frosted or opaque bathroom window that lets in light but does not allow a clear view, and this is somewhat like the change the lens undergoes when a cataract develops.

Cataracts are a natural part of ageing and are the leading cause of vision loss among adults 55 and older. They can also exist at birth (congenital cataract); be caused by an injury (traumatic cataract); some medications; or be caused by conditions like diabetes or severe glaucoma. The vast majority of people with cataracts are extremely healthy and have no other eye disease. Cataracts usually develop in both eyes, although not always at the same rate. Their rate of development will vary from person to person, but generally develop slowly over a period of time. Occasionally the effect on vision, however, can be faster, occurring over a period of several weeks.

Specialists

Symptoms

Individuals notice cataracts in different ways depending on their day to day activities. As the cataract develops, they may notice any of the following:

Deterioration of distance and reading vision

The vision may seem dull and colours appear less bright

Sensitivity to light

Glare intolerance (especially at night)

Double vision or halos around lights

Becoming more myopic (short-sighted)

Treatments

Cataracts may be noticed during reading, watching television, driving (particularly at night) or any other activity. Currently, there is no medical treatment (drops or tablets) that will prevent cataracts or reverse them once they develop. Surgery is the only treatment.

The decision to proceed with cataract surgery is an individual one and made in consultation with the patient’s ophthalmologist. The timing of surgical intervention will vary, depending on the degree to which the cataract is impairing the patient’s vision and the effect this is having on the patient’s lifestyle.